1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
4 * Author: Marc Zyngier <marc.zyngier@arm.com>
7 #include <linux/acpi_iort.h>
11 #include <linux/of_irq.h>
12 #include <linux/of_pci.h>
14 static void its_mask_msi_irq(struct irq_data *d)
17 irq_chip_mask_parent(d);
20 static void its_unmask_msi_irq(struct irq_data *d)
22 pci_msi_unmask_irq(d);
23 irq_chip_unmask_parent(d);
26 static struct irq_chip its_msi_irq_chip = {
28 .irq_unmask = its_unmask_msi_irq,
29 .irq_mask = its_mask_msi_irq,
30 .irq_eoi = irq_chip_eoi_parent,
31 .irq_write_msi_msg = pci_msi_domain_write_msg,
34 static int its_pci_msi_vec_count(struct pci_dev *pdev, void *data)
36 int msi, msix, *count = data;
38 msi = max(pci_msi_vec_count(pdev), 0);
39 msix = max(pci_msix_vec_count(pdev), 0);
40 *count += max(msi, msix);
45 static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
47 struct pci_dev **alias_dev = data;
54 static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
55 int nvec, msi_alloc_info_t *info)
57 struct pci_dev *pdev, *alias_dev;
58 struct msi_domain_info *msi_info;
59 int alias_count = 0, minnvec = 1;
64 msi_info = msi_get_domain_info(domain->parent);
66 pdev = to_pci_dev(dev);
68 * If pdev is downstream of any aliasing bridges, take an upper
69 * bound of how many other vectors could map to the same DevID.
71 pci_for_each_dma_alias(pdev, its_get_pci_alias, &alias_dev);
72 if (alias_dev != pdev && alias_dev->subordinate)
73 pci_walk_bus(alias_dev->subordinate, its_pci_msi_vec_count,
76 /* ITS specific DeviceID, as the core ITS ignores dev. */
77 info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
80 * Always allocate a power of 2, and special case device 0 for
81 * broken systems where the DevID is not wired (and all devices
82 * appear as DevID 0). For that reason, we generously allocate a
83 * minimum of 32 MSIs for DevID 0. If you want more because all
84 * your devices are aliasing to DevID 0, consider fixing your HW.
86 nvec = max(nvec, alias_count);
87 if (!info->scratchpad[0].ul)
89 nvec = max_t(int, minnvec, roundup_pow_of_two(nvec));
90 return msi_info->ops->msi_prepare(domain->parent, dev, nvec, info);
93 static struct msi_domain_ops its_pci_msi_ops = {
94 .msi_prepare = its_pci_msi_prepare,
97 static struct msi_domain_info its_pci_msi_domain_info = {
98 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
99 MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
100 .ops = &its_pci_msi_ops,
101 .chip = &its_msi_irq_chip,
104 static struct of_device_id its_device_id[] = {
105 { .compatible = "arm,gic-v3-its", },
109 static int __init its_pci_msi_init_one(struct fwnode_handle *handle,
112 struct irq_domain *parent;
114 parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
115 if (!parent || !msi_get_domain_info(parent)) {
116 pr_err("%s: Unable to locate ITS domain\n", name);
120 if (!pci_msi_create_irq_domain(handle, &its_pci_msi_domain_info,
122 pr_err("%s: Unable to create PCI domain\n", name);
129 static int __init its_pci_of_msi_init(void)
131 struct device_node *np;
133 for (np = of_find_matching_node(NULL, its_device_id); np;
134 np = of_find_matching_node(np, its_device_id)) {
135 if (!of_device_is_available(np))
137 if (!of_property_read_bool(np, "msi-controller"))
140 if (its_pci_msi_init_one(of_node_to_fwnode(np), np->full_name))
143 pr_info("PCI/MSI: %pOF domain created\n", np);
152 its_pci_msi_parse_madt(union acpi_subtable_headers *header,
153 const unsigned long end)
155 struct acpi_madt_generic_translator *its_entry;
156 struct fwnode_handle *dom_handle;
157 const char *node_name;
160 its_entry = (struct acpi_madt_generic_translator *)header;
161 node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
162 (long)its_entry->base_address);
163 dom_handle = iort_find_domain_token(its_entry->translation_id);
165 pr_err("%s: Unable to locate ITS domain handle\n", node_name);
169 err = its_pci_msi_init_one(dom_handle, node_name);
171 pr_info("PCI/MSI: %s domain created\n", node_name);
178 static int __init its_pci_acpi_msi_init(void)
180 acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
181 its_pci_msi_parse_madt, 0);
185 static int __init its_pci_acpi_msi_init(void)
191 static int __init its_pci_msi_init(void)
193 its_pci_of_msi_init();
194 its_pci_acpi_msi_init();
198 early_initcall(its_pci_msi_init);